Biological Laboratory, Urmond College. 14-3 



rate was slow at first, then gradually ([uickened, attained its 

 maximum speed, and finally declined. The greatest speed 

 attained was found to be a complete revolution in If minutes. 

 Left. — For 15 recorded revolutions, the slowest was 17 minutes, 

 the quickest 2J minutes, and the average 6 minutes. The 

 first revolution took 11 minutes, and the last (recorded) 

 17 minutes. If a partial average be taken, including from 

 the 4th to the 12th round, when the rate was comparatively 

 regular, it would give 3 minutes per round. The left 

 reversed, performed 12 revolutions at an average rate of 

 8 minutes. The motion was very steady, and after the first 

 round, which took 16 minutes, the rate was either 7 or 

 8 minutes. A second specimen tried, performed 1 2 revolu- 

 tions at an average rate of 6J minutes. The first round 

 took 10 J minutes, and afterwards they varied from 7 J 

 to 5 minutes. It is always to be understood that the 

 palp continued revolving after the recorded observations. 

 Right. — For 26 recorded revolutions, the slowest was 

 60 minutes, the quickest If minutes, and the average 

 8J minutes. It commenced with a revolution in 5 minutes, 

 about the middle (14th) attained to the quickest in If minutes, 

 and ended with the slowest in 60 minutes. A partial average 

 for the more steady rounds, comprising from the 6th to the 

 19th inclusive, gave 2 J minutes per round. The record was 

 closed for the right after completing 26 rounds, when it 

 became perfectly still, as if exhausted. It was still sensitive, 

 however, as it quivered on being touched with a pin, and 

 next morning it had shifted its position. The right reversed, 

 moved very slowly, although it rotated in the usual manner 

 by making the base the pivot. The first round occupied an 

 hour, but deducting time stuck, it only took 28 minutes ; 

 the second round 22 minutes, and the third 20 minutes. 

 Another specimen was tried, and in 12 revolutions gave an 

 average rate of 5^ minutes per round. The first round took 

 7 J minutes, the last 8 J minutes, and the intermediate rounds 

 from 4 to 5 J minutes. 



2. — Outer Palps. 



The movements generally resemble that of the inner palps. 

 The outer palps appear to be capable of more sustained efibrt 

 than the inner, as indicated by their more regular rotation 

 for longer periods. The tip appears to be exceedingly 

 sensitive. It might be thought from their general resemblance 



